1. Field of the Invention
This invention relates generally to pharmaceutical acetylcholine products. In a preferred embodiment, the invention relates to ophthalmic acetylcholine products.
2. Description of the Related Art
Anterior segment surgery of the eye is relatively common today. These surgical procedures include cataract surgery, penetrating keratoplasty and iridectomy.
Post-surgical treatments are also common. A typical treatment which follows anterior segment surgery involves an immediate application of a pharmaceutical agent which increases the rate of miosis (i.e., constriction of the iris). A preferred miosis-inducing pharmaceutical is acetylcholine, and the chloride salt is the preferred salt. Acetylcholine is also called 2-(acetyloxy)-N,N,N-trimethyl-ethanamium; chloride; acecoline; or arterocoline.
An outstanding product for increasing the miosis rate is sold under the trademark Miochol.RTM.-E, which is an intraocular acetylcholine solution marketed by CIBA Vision Corporation, Duluth, Ga. Since aqueous acetylcholine solutions are unstable, the Miochol.RTM.-E product is packaged in a vial having two compartments or chambers which are separated from one another by a rubber stopper. The lower chamber contains 20 mg of acetylcholine chloride and 56 mg of mannitol. The upper chamber contains 2 ml of a diluent of sodium chloride, potassium chloride, magnesium chloride hexahydrate, calcium chloride dihydrate and sterile water for injection.
In use, an eye care professional turns a plunger-stopper mechanism a quarter turn and presses to cause the rubber stopper to dislodge and allow diluent from the upper chamber to pass into the lower chamber, thereby mixing the two solutions. The solution is then administered via injection into the anterior chamber (e.g., seconds after a lens has been inserted during cataract surgery), either before or after securing one or more sutures.